1. Field of the Invention
The present invention relates to a tracking error signal (TE) detection apparatus using differential phase detection (DPD) in an optical disc or similar apparatus, as well as to an optical disc apparatus.
2. Description of the Related Art
In optical disc controllers, a DPD tracking error (TE) detection apparatus (i.e., circuit) is often provided in order to generate a TE signal for ROM-type discs. Currently, such DPD TE detection apparatus are realized by means of high-speed, high-precision analog circuits (see, for example, Japanese Patent Nos. 3336778, 3065993, 3439393, and 3769888, and Japanese Unexamined Patent Application Publication Nos. S57-191839, S57-181433, S63-148433, H07-296395, S63-131334, and 2006-260645).
Meanwhile, however, the integration of analog signal processing and digital signal processing onto a single chip has been progressing in recent years, in conjunction with the development of system LSI technology. Optical disc controller chips are not an exception to this trend. Thus, in conjunction with the development of the increasing digitization of signal processing, there is demand for DPD TE detection apparatus to be integrated onto a digital chip.
Technology designed to meet this demand will now be described using the following examples 1 to 3.